1. Field
This invention relates generally to automatic firing guns, specifically to a type of gun known as a submachine gun and, more particularly, to a simplistic assembly arrangement for rigidly coupling together the gun subassemblies.
2. Prior Art
The value of any gas-operated projectile firing weapon, whether it be of a large or small caliber, is its accuracy and reliability for delivering fire on target. The market for automatic weapons is with law enforcement agencies and the military, where the weapon must sometimes be operated under adverse conditions and, yet, will still function reliably to deliver accurate fire on target. It is essential with fully automatic weapons, such as a machine gun or submachine gun, that the weapon fire consistently without jamming.
The present invention is an evolutionary outgrowth of and improvement on certain other U.S. patents; specifically, patents by R. J. Casull, U.S. Pat. Nos. 3,319,523 (1967) and 3,366,010 (1968), and later patents by Brandstatter et al., U.S. Pat. Nos. 3,969,980 (1976) and 3,969,981 (1976). These earlier patents were a basis for development and manufacture of a weapon known as the American 180 and show and describe an efficient and reliable weapons system capable of delivering a high volume of low caliber fire accurately on target, with almost no barrel climb, the present invention being an improvement thereon.
The present invention improves on the structure of the above-cited art, providing interlinking structures whereby, with only a single barrel retaining screw, the component assemblies are maintained together, holding a bullet cartridge feed block in position relative to the barrel and receiver groups and in alignment with a cartridge feed opening of a drum-type magazine. So arranged, cartridges fed from the magazine will be exactly aligned by the feed block for pickup from the undersurface thereof, in turn, by a reciprocating bolt. The bolt movement, in conjunction with the cartridge feed block mechanism, cams the cartridge off the feed block undersurface into the barrel breech for firing, with back travel of the bolt pulling spent cartridge casings from the barrel breech and ejecting them from a receiver cartridge exhaust. Where early arrangements, including the above-cited patents, have involved a number of pins, screws, bolts, or the like for fitting through aligned openings of the respective weapon groups, the present invention, by its interlocking assemblies, provides a gun that can be assembled and disassembled in a phenomenally short period of time, where the component assemblies are tightly coupled and the relative distance between the receiver and barrel groups is fixed to provide an optimum head spacing between the firing pin and the barrel breech. In a field setting, a person, with only a basic familiarity with the weapon, and little instruction, can easily assemble and disassemble the gun and perform basic cleaning and oiling thereof, including replacement of components such as the bolt.